I have two copies of the same card. Which will I give away if I offer one in a trade?

When a collector owns more than one of the same card, the highest numbered card is always traded away.  For example, a collector who owns card #2 and card #202 will always give away card #202 first. This happens regardless of whether the collector has started the trade or is responding to another collector's offer.  Having this rule ensures a collector won’t accidentally trade away cards with low numbers, which are typically valued by collectors more highly.